BBN has developed flexible counter-sniper technology capable of shooter and bullet trajectory localization using fixed, vehicle-mounted, and/or body-worn microphone sensors. The proof of principle (POP) systems developed are accurate, low-cost, lightweight, and easy to install and use. The use of both supersonic bullet shock waves, and/or the muzzle blast, allows detection and localization of shooters with intentional or accidental muzzle blast suppression, or with subsonic rounds. This makes the system capable of finding shooters firing from within buildings or vehicles. It also requires fewer sensor installations per unit area and increases system robustness to the noise and reverberation present in urban settings. In this paper we first summarize the current POP system hardware and software configurations and show the results of government testing in urban and rural environments for military applications. Following this, cost and performance issues for urban law enforcement applications are presented, and performance predictions for various system configurations in an urban street monitoring scenario are given.